Folding Forum

I have a 24-CPU system that for various reasons I cannot upgrade to enable 0xa7 WUs to be processed (shared libraries are old versions, which causes 0xa7 WUs to fail).

I have set max-packet-size to "small" and for a long time this seemed to favour 0xa4 WUs to be processed. For the last few days, only 0xa7 units seem to be downloaded (all of which fail as described above).

Conversely I have a couple of systems that process 0xa7 units *much* faster than 0xa4 ones - any way to force these systems to only download 0xa7 WUs ?

Thanks for any help

Hi Blue_Bubble,

For the first question: 0xa7 work units are only deployed if the CPU and OS support AVX instructions. So if you can somehow disable AVX support in BIOS or OS then you will only get 0xa4 work units anymore. On Windows in a cmd shell enter this: "bcdedit /set xsavedisable 1" and reboot but I don't know if this could lead to problems like not booting or others.

For the second question: no you cannot force 0xa7 only as there are also 0xa4 work units which need to be processed.

foldy wrote:For the first question: 0xa7 work units are only deployed if the CPU and OS support AVX instructions. So if you can somehow disable AVX support in BIOS or OS then you will only get 0xa4 work units anymore.

That may seem true, but it's really not so.

There are two versions of 0xa7. They run exactly the same group of projects but one is compiled to use AVX and it's deployed, as you say, to CPUs and OSs which support AVX. The other is compiled to use SSE2 instructions, and it's assigned to the same machines which run 0xa4 projects.

Blue_Bubble wrote:Conversely I have a couple of systems that process 0xa7 units *much* faster than 0xa4 ones - any way to force these systems to only download 0xa7 WUs ?

As foldy has said, you cannot force a system to download only 0xa7 assignments. On a platform that supports AVX, these WU will use the AVX version of 0xa7. If assigned to a platform which does NOT support AVX, the second version of FAHCore_a7 will be deployed. In that case, that system will use SSE2 instructions and FAHCore_a7 will process that assignment at the same speed as it would run 0xa4.

i.e. - both types of platforms will receive both types of assignments.

If you post segments of your logs from both types of systems where it starts processing both types of assignments, we can point out the difference. Use the instructions below, but be sure to include the long lines of the form Running FahCore: "C:\Program Files ... FahCore_a4.exe -dir 00 -suffix 01 -version .... for both a4 and a7 and note whether you believe the system supports AVX or not.

>>>>>>>>>>>>>> Hardware and OS
>>>>>>>>>>>>>> AVX _____non AVX
Project uses
>>>>> 0xa4 >>> SSE2 ______SSE2
>>>>> 0xa7 >>> AVX ______ SSE2

Blue_Bubble wrote:Conversely I have a couple of systems that process 0xa7 units *much* faster than 0xa4 ones - any way to force these systems to only download 0xa7 WUs ?

I suspect no truly new research is being started with a4 cores. It could take years for all current and subsequent research to finish. Once all those a4's are done, a7 will be the new normal.
While currently a7 requires a 64 bit OS, it is not a given that 32 bit CPUs can't run it eventually. If not, then Netburst through Core Duo will be retired when a4 runs out.

I have an old server in the same situation ... so it regularly fails A7 WUs and there's nothing I can do about it (I tried to update the Ubuntu distribution, but it's too old now and it can't even update).

Post the log showing the log around the time of a couple of failures.

It's just incompatible libraries with this old Ubuntu 10.04 setup ...